Experimental Research On The Crack Width And Deflection Of The500MPa Reinforced Concrete Beams And Columns

500MPa fine grain reinforced concrete structures have good bearing capability.The existing norms in our country which is called "Design of Concrete Structures"(GB50010-2011) regulates the design of its tensile strength is435MPa, which is1.2times of the HRB400steel. In the case of using the same amount of steel, the use of500MPa steel can improve the bearing capacity of components. Under the effect ofnormal usage limit state of the high stress, the stress of components is higher and thedeformation is larger. So in the state of normal use of non-pre-stressed members, thecrack width and deflection of the component may be the main controlling factor in thecomponent design.Based on the comparative experiment between the (1) three500MPa fine grainreinforced concrete beams and a reinforced concrete beams HRB335, and the bias testbetween the (2) six500MPa fine grain specimens reinforced concrete columns and areinforced concrete eccentric HRB400compression column, this thesis will come to abasic understanding of the crack width and deflection of the components under thecolumn bias state of500MPa fine grain reinforced concrete beams.It has been confirmed form the experimental research that the500MPa fine grainfailure mode of reinforced concrete, the basic characteristics of deformation is thesame with the fracture of reinforced concrete structures. And the failure mode can bedivided into reinforced concrete compression failure and tensile failure. Like theordinary steel of HRB400level, the strength of the500MPa fine grain steel can befully utilized as when the force as a reinforcement for flexural members and thecolumn bias. And the bearing capacity can be calculated by using the relevant formulaof the existing "Design of Concrete Structures "(GB50010-2011).In this thesis, it is found from the analysis of the experiment for the four bendingsimply supported beams that the flexural crack width and deflection componentsmeet the controlling requirements of the current regulation. The flexural propertiesof the500MPa fine grain reinforced concrete and the ordinary reinforced concrete are the same, with good mechanical properties, and ductile fracture can be achieved.The analysis of the experimental results of the seven large bias column shows thatthe relevant formula of the existing norms that concerning the calculation of theaverage crack spacing and the maximum crack width can be better used for500MPafine grain reinforced concrete eccentric compression.In accord with the basic theory of reinforced concrete structure, this paper madean analysis on the fine grain of500MPa reinforced concrete beams and the forcemechanism of the bias columns. In addition, this paper compared the forcecoefficients of the component valuesαcrand found: When calculating according tothe standard combination, the bias component columns and beams the forcecoefficients obtainedstent and haαvcer a=g o1o.d9for maximum crack calculations and test valuesmore consi safety margin; when taking quasi-permanent valuecalculation, taking columnαcr=1.7, bending members coefficient of themechanical characteristic of the maximum crackαcr=1.9for the calculation, thereliability between the bias component and bending members are the same, and thereis enough safety margin.